Conductive bumps are presently being used in a variety of ways in conventional electronic devices and, particularly in, semiconductor device packaging. For example, conductive bumps are widely used for interconnect between ceramic or organic substrates and printed circuit boards, between die pads and base substrates, and between die surfaces. The conventional conductive bumps comprise metallic materials. Some examples of commonly used metallic materials are Sn, Pb, Ag, In, Bi, Au, Sb, in either their pure or alloyed forms.
The conventional metallic conductive spheres give rise to significant problems and disadvantages within the context of electronic device packaging. More specifically, prolonged thermal treatments of alloyed metallic materials can cause segregation of base metals and unwanted intermetallic formation. This segregation of base metals and intermetallic formation can cause electrical and thermal conductivity problems and loss of mechanical integrity. There are also significant problems associated with the requirement to apply flux to reduce the metallic oxidation and obtain a solderable interface. Many flux applications require cleaning of the flux residues after soldering, and possible ionic contamination associated with certain types of flux materials.
Consequently, what is needed is an electronic device having conductive interconnect paths which do not form intermetallics, oxidize, or require cleaning of flux residues, and which will not exhibit loss of structural integrity for these reasons.